#define _CRT_SECURE_NO_WARNINGS
class A
{
public:
	int _a;
};
// class B : public A
class B : virtual public A
{
public:
	int _b;
};
class C : virtual public A
{
public:
	int _c;
};
class D : public B, public C
{
public:
	int _d;
};
int main()
{
	D d;
	d.B::_a = 1;
	d.C::_a = 2;
	d._a = 3;
	d._b = 4;
	d._c = 5;
	d._d = 6;
	return 0;
}